I currently have a 97 Expedition XLT 4x4 with 4.6 and 4R70W. What all is involved to swap a 5.4 and trans in? Is the wiring harness compatible? Do I just swap the motor, trans, and PCM? Driveshafts? Will the transfer case bolt up?

 

The 5.4 will bolt right up to your exsisting tranny. Just be sure to use the 5.4's flex plate. You will need to use the 4.6 harness and get a chip to handle the engine controls. Two sensor wires will need to be extended. The oil pressure sensor and the IAC. The 4.6 wires are too short.

JMC